When designing power supplies and power conversion systems, significant compromises in energy efficiency must be made in power switch device selection due to the limitations imposed by the switching characteristics of the available switching elements. A MOSFET is capable of fast switching and hence low switching losses, but has limited current-density capability, both of which are due to the majority-carrier nature of the device. An IGBT, on the other hand, is a minority-carrier device which can achieve very high current-density but is limited in switching speed by minority-carrier-lifetime-induced tail current which results in extended turn-off time and thus higher switch-off energy loss compared to the MOSFET. The subject of this invention is an optimal device that combines the best characteristics of both of these types of devices.